ixed points. It was about seven miles
south-west of our camp; but after a most fatiguing ascent of two steep
and rocky ridges, during great heat, I was obliged to return without
reaching Marga. At the cattle station we heard of a bullock which had
been left by us in an exhausted state during our last expedition; and we
succeeded in bringing it in, and in laying the yoke on its neck for
another visit to the banks of the Darling; it was fitter than any other
of our working bullocks. I added a second species of Psoralea to that
discovered yesterday, a small graceful plant with racemes of purplish
minute flowers, elevated far above the leaves, and on slender stalks so
tough as to be broken only with some difficulty.*

(*Footnote. P. tenax, Lindley manuscripts; herbacea, depressa, perennis,
glabra, foliis glandulosis palmatim 5-foliolatis, foliolis linearibus vel
lineari-oblongis obtusis, racemis cylindraceis longissime pedunculatis
erectis, leguminibus ovatis scabris glabris.)

March 21.

According to arrangements made with Captain King and Mr. Dunlop, the
King's astronomer at the Parramatta observatory, I halted the party this
day in order to make hourly observations of the barometer, thermometer,
the sky, etc. This plan had been strongly recommended by Sir John
Herschel; and for our present purposes it was most desirable in order
that we might ascertain how far the fluctuations of the atmosphere in two
places so distant as Parramatta and Byrne's creek corresponded in these
simultaneous observations. During our last journey some discrepancies in
the heights determined by the barometer on the Darling led to a suspicion
that the fluctuations at such great distances, in situations so
dissimilar, might vary considerably; and this was now to be ascertained.

THE PARTY IMPEDED BY ROCKS.

March 22.

We continued our journey along the left bank of the creek, but with
considerable difficulty and delay occasioned by the projection of the
rocky escarpment of the above-mentioned extremities of Mount Marga; so
that we had to break away masses of rock and move the carts one by one,
all hands assisting. We at length gained a pleasant tract of land on
which the grass was green and luxuriant in consequence of some partial
rain; and on this place I encamped with the intention of next day
ascending Marga. In the creek we found ponds, deep and clear like canals;
their borders being reedy and their margins green. In these ponds the
nati